If there's any sort of space combat in the future, there's going to be a very large number of "dumb kinetic weapons" as a result, whatever "official" weapons you're using. Shrapnel.

>I think one of them would be a blanket ban on dumb kinetic weapons.

nope. The perceived danger of dumb kinetic weapon is a relative speed to the target, ie. kinetic energy. It means that either target or shooter has technological ability to control the energy at respective level. Lets suppose both - i.e. symmetric situation of the same technological levels on both sides. Thus the opponent can deploy similar energy level devices as a defense. For example - today an anti-ship missile can be fought against by using anti-anti-ship missile or guns. New laser defense systems are able in realtime to defend against incoming mortar round today, etc... By the time somebody puts sand in space, an automated laser space junk frying Roombas would be just naturally flying around.